1. Solder together a 1N904 diode and wire together (repeat step again for 2 wires)
2. Solder the 1N904 wire to the positive side of the solar panel.
3. take a battery pack and solder the two leads to the 2 1N904 wires that are connected to the solar panel. (Make Sure the Positive is connected to the positive, and negative is connected to the negative.)
4. Solder on the 5v USB charging circuit to the positive and negative leads from the battery pack.
P.S Use a multimeter to check the voltages and current and see if the led on the usb charging circuit lights up.
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